The present invention relates to exhaust systems, including exhaust systems for automobiles. Motor vehicles are the major sources of carbon monoxide and hydrocarbons. In the United States gasoline and diesel vehicles produce about 70 percent of the carbon monoxide, 50 percent of the hydrocarbons, and 35 percent of the nitrogen oxides (Laurent Hodges, "Environmental Pollution"). Acid rain and unique Los Angeles-type smog are proof of importance this problem.
Many exhaust gas cleaners are known, but none of them are completely satisfactory. Most of the existing cleaners comprise spray cleaning device to remove pollutants.
Pickering, U.S. Pat. No. 4,821,513, shows an automobile exhaust gas cleaner having a plurality of gas permeable baffle plates being sprayed with a cleaning liquid from a series of nozzles to clean the exhaust gas.
Nishinomiya, U.S. Pat. No. 3,738,085 shows a device for the removal of detrimental matter from exhaust gases. This device has a tank with mixing liquid consisting of water, phosphoric acid, peroxide of barium and peroxide of hydrogen which is dropped into the drum. Further mixing liquid is dispersed and evaporated for cleaning.
Such cleaning devices are not satisfactory. Each device relies upon expansion of the exhaust gases within the device to cool the gases and cause the vapor to condense. The contact of the exhaust gases with mixing liquid in case of spray means or dropping liquid is limited.
There are also catalytic devices to convert carbon monoxide into carbon dioxide. These devices are expensive and have low efficiency.